Feed-regulator for grinding-mills.



J. s. FASTING. FEED REGULATOR FOR GRINDING MILLS. APPLICATION FILEDNOV.13, 1914.

1,157,979. Patented Oct. 26, 1915.

2 SHEETS-SHEET I.

1 .5 4 5 C q 1 1 f d fi I [fii k 5 5' 577w 549- w I WITNESSES wtazz mwJ. S. FASTING. FEED REGULATOR FOR emwome' MILLS.

APPLICATION FILED NOV. 13, 1914.

Patented Oct. 26, 1915.

2 SHEETSSHEET 2.

WITNESSES:

TTORNEYJ JOHAN S. FASTING, O-F FREDERIKSBERG, NEAR COPENHAGEN, DENMARK:

FEED-REGULATOR non GRINDING-MILLS.

Specification of I.etters Patent. 7

Patented Oct. 26, 1915.

Application filed November 13, 1914. Serial No. 871,851.

, To all whom it may concern:

Be it known that I, J OHAN S. FASTING, a

subject of the King of Denmark, residing in F rederiksberg, nearCopenhagen, Denmark, have invented certain new and useful Improvementsin Feed-Regulators for Grinding-Mills, of which the following is aspecification, reference being had to the accompanying drawings, forminga part hereof. I

This invention relates to high speed grinding mills in which thematerial to be ground is carriedup the side of a rotating mill withsuitable grinding bodies, such as balls, and permitted to tumble downupon itself in such a manner as to crush or pulverize the particles ofthe material. One of-the primary considerations in the operation of amill of this character is the speed of grinding of the material, that isto say, it is important that the material shall pass through the mill asrapidly as possible in order that the quantity ground in any unit oftime shall be a maximum. Under some conditions of use, it becomespossible to rotate the mill at a speed higher than the critical speed,so that the material is carried around the wall of the eventually pointof efiicient operation, will be acted on mill by centrifugal action andpermitted to have a relatively short drop for the pulverizing action.When themachine is rotated at such a speed, however, the .tendency isfor the material to gather in the mill and prevent any cascading orpulverizing movement.

The present invention has for its principal object to provide deviceswhich will increase the output of a mill of the character referred toand to provide devices in combination -with the .mill for regulatingthespeed of rotation thereof or the rate of feed of the "material intothe mill.

In accordance with the invention, what may be termed aregulator arm, orits equivalent, is positioned within the mill so that normally it willnot interfere with or be touched, by the grinding bodies or thematerial, but which, when the rate of feed or the speed of the millexceed a predetermined by the grinding bodies and the material and willbring about a reduction in the rate of feed of the material or areduction in the speed of rotation of the mill. The control referred tois mentioned merely as an illustration of two feasible ways in which thedesired purpose may be accomplished, which is, the increasing of thecapacity of a,high speed mill, but it will be understood as thisdescription proceeds that the mechanical actlon on the regulator arm maybe converted into useful work for thepurpose of control- Figure 1 is aview partly in vertical section and partly in elevation of a completeplant constructed in accordance with the present invention and showingthe regulator arm connected to the feed valve of the material wherebythe rate of feed may be controlled. Fig. 2 is a sectional viewv taken onthe plane indicated by the line 22 of Fig: 1 and looking in thedirection of the arrows. Fig. 3 is a view in end elevation of the millshown in Fig. 1. Fig. 4 is a view, partly in vertical section and partlyin elevation, of a complete plant constructed in accordance with thepresent invention and showing the regulator arm connected to thecontrolling,

member of the driving motor for the drum may be controlled.

The high speed grinding mill a may be of any approved type,.having meansfor feeding the material thereinto, such means being illustrated hereinas a screw conveyer b disposed with its inlet directly beneath adischarge opening 0 formed ,in a hopper c, the area of the dischargeopening and the rate of feed of the material therethrough beingcontrolled by a suitable valve d. The screw conveyer b may be rotated bypower applied to its shaft 6 in any approved manner. The material may bedischarged from the mill through openings a] formed in the dischargehead thereof from whence it passes into a casing c, all as is wellunderstood.

During rotation of the mill counterclockwise, as indicated in Fig. 2,the material with the grinding bodies, such as balls, is carried up theside of the wall for a certain distance cading effect referred to cannotbe effectivefor the grinding action demanded. In accordance with thisinvention this difliculty is overcome by providing within the mill, adevice, such as the arm 7, which will be struck by the material and thegrinding bodies when the capacity of..the mill is exceeded. On the otherhand, during the normal operation of the mill, the material does nottouch this regulator arm. In the embodiment illustrated in theaccompanyingv a which is of appreciable weight, may be posithe other ofthe arm tioned with its center of gravity outside of its base-and thisunbalanced weight may be counterbalanced by means of a counterweight gsecured to'the sheave f 1 i In operation, the material is fed into themill at such a rate and the mill is rotated at sucha speed, by anannular gear a ,-that the material and grinding bodies are permitted tocascade either to one side or to g, without touching the arm, thiscondition eing maintained until the capacity of the'mill is exceeded. Ifthe material accumulates in the mill so that its thickness prevents thecontinuance "of the {cascading movement, it will contact with theregulator arm 7 and bear the same downward so as to rock the shaft f andbring about a artial closing of the valve aZ. The rate of eed of thematerial will thereby be,

decreased until such time as the material assumes its normal cascadingmovement and falls free of the regulator arm. The result is that thequantity of material within the mill is regulated at all timesautomatically for a given speed of rotation and the mill may accordinglybe operated at its maximum capacity.

It should now be understood that the construction of the regulatingdevices may be varied widely,.it being necessary only that there bewithin the mill, some member which is acted on mechanically by thegrinding bodies or by the grinding bodies and the material when thecapacity of the mill is exceeded and that this member should beconnected operatively without the mill with controlling rheostat-i, thearm z" of which 4 may be weighted, as at 13 to move the arm in onedlrectlon and may have secured thereto the free end of the'chain 7, thelatter being connected operatively to the arm 7 in the same manner asdescribed with respect: to the embodiment shown in Fig. 1. The rheostati is so formed that whenever the material and grindin bodies, or'-eitherof them, bank up in the rum a and act on the arm f, ,the rheostat. arm71 willbe moved to increase the speed of rotation of the motor h and thedrum. Asthe speed of rotation increases, it will be understood that thematerial is discharged more rapidly so that for any given rate of inflowof the material past the valve d of the hopper 0, the speed of rotationwill be so controlled automatically as to regulate the rate of dischargeof the material and thereby insure'the operationof the mill at itsmaximum capacity,

in Fig. 1'.

The general scope of the invention having now been pointed out and adetailed description of one form of apparatus for practicing theinvention having been given, it remains to define the general scope ofthe invention by the appended claims.

I claim as my invention 1. In a grinding mill, the combination with thegrinding bodies, of means disposed within the mill to governautomatically the supply of material to the mill or the speed ofrotation thereof, said-means being disposed within the mill and mountedout of the path of the material during the normal operation of the mill,but adapted to bev struck by the material and grinding bodies and movedwhen the capacity of the mill is exceeded, such movement serving toeffect the said governing action.

2. In a high speed grinding mill, thecombination with the grindingbodies, ofavalve to control the inflow of the material to be ground, andmeans disposed within the mill and connected operatively to said valveto govern the position of the valve, said means including an armarranged out of the path of the material during the normal operation ofthe mill but adapted to be struck by the material and moved when thecapacity of the mill is exceeded, such movement serving to move thevalve to decrease the inflow of the material.

3. In a high speed grinding mill, the combination with the grindingbodies, of a valve 7 to control the inflow of the material to be ground,means disposed within the mill and connected operatively to said valveto govvat ern the position of the valve, said means interial and movedwhen the capacity of the mill is exceeded, such movement serving to movethe-valveto decrease the inflow of the material, and means cooperatingwith the valve to restore it automatically to its normal position uponresumption of normal operation of the mill.

4. In a high speed grinding mill, a hopper for the material providedwith a discharge opening and valve to control-the flow of materialthrough the discharge opening into the mill, a shaft passing through thedischarge head of the mill and arranged axiallyiof the mill, an arcuatearm carried on the inner end of the shaft and disposed radially of themill, a sheave mounted on the outer end of the mill, an operativeconnection between the sheave and the valve, and a counterweight carriedon the sheave to maintain the radial arm in normal position, the armbeing arranged to be struck by the material and'moved to close the valvewhen the capacity of the mill is exceeded, the. counterweight serving torestore the valve to its normal position as soon as the mill againoperates at its normal capacity.

This specification signed and witnessed this 17th day of October A. D.,1914.

J OHAN S. FASTING.

Signed in the presence of AXEL PERMIER,

OHR. ENGELHART.

